SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c639c64b05422f0e66ddcbe74ce96276adcf79ad7b3a950719dfbc2f97b933cd' 
  AND token = 'avkeoYZNRImLYfI66XDS2puTqybgl2REIILFKqXmnr4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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