SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f220b49a52895ef525c07ad9631a5d56258e6d6752538b6e7c8901b2c746642c' 
  AND token = 'gi8vLEHKzSYjf1Kpe2n2JTCMHgCR4EnG0H+gqZ21Ybs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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