SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd2524429849e2a250a9376d50bdc9be5e3eada8440b604b53f2c22a1bd3cf80a' 
  AND token = '7cskspWLCWgGLvX+mK3Bx4yDBPrSQyM1uFooPMnxwnw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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