SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f4a7f0fb18ba2c7b4b15df41fcebb239698f3eab89cde196487cce528615a4e2' 
  AND token = 'fmRFt4+qWwiXCba+L0GJgoLWv/JYaczB67z3G3dwTsY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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