SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8fc92d881f29193b54af2b6e9ff1a22950abaeba4bf85a544bae200f5a779f35' 
  AND token = 'rX4Kj5fTHK7DMhwqo2V7LOTHThrLvGg4o/P5YUumqSA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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