SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a22ed381bf6be380fef09ea9d0e2bcdfd15a7549f09d00683c4202efc73d34f4' 
  AND token = '1uDnnpZjFoDbHEzD6jWft247/Gyp4Qb17tNeDYRagDE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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