Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a4f9378d52de7b4f804ba13e35e3c755e19fa8fa35b65f7a7442907f83dbeda7' 
  AND token = 'X/RU/Rqaj94yBZtLWWe0aHcoDHJK4ZmS4bQ99UeJMcE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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