SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9d19d3ab2a1233424af38f3479fc3870c64ecbe9275f19247a790626c0639266' 
  AND token = 'vIbxe1TTY5/gUrQiL43Hjm6RRolc9vB9Ff6JmiNYMhc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}