SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1f28bc7254c62e98497c08b023c898d1a4bfbe240e826f0a3b12e0d9899e2f86' 
  AND token = '0Fi4zM1rOstOvDygDZhD7ljYEQ19awZvjbu09ooJwHY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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