SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '99ffd200a30ad24fe7600cc69ca5a2414ff758654d0edabd7b41e7f06f3bd206' 
  AND token = '2HoIRDtCi0f6PC//psS8psJbzwhq1Q5rr4v0rPbb7LM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}