SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'be04496ffe9106c0ea7944e6add3446d788ff1a6b454e53d37565ae4872664d0' 
  AND token = 'Nuw7AiOIGmCXEYWzQSCEgBEf6Xq85ocf2OfFAFaPoZs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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