SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8e1369e54ea775cfbc06c0a6344259dfe8fd60ac0e3e6c1c31243c02b28fdc9f' 
  AND token = 'sFEufGQUxqTfWlEeu/Csgpix9fh39DyS5NCkSMNgg8w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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