SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0d3bf5a4ac82cdfced178dd9889a5f74277aebbcef4b529936b1874ecd725634' 
  AND token = 'NJTZ5tn1DCGKUWvsz2qhuhV7j/mwvaizSEFW7UdstCM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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