SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3ffdeb0cf2efe9e3825a4228b991787dfe97b1f8c982884c05a99cd0db8f834c' 
  AND token = 'Y7lcoTycjyNVujM2zQ7abipiWkTQlArSllCtsdCcnH4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}