SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a1d4851764c953998b9e1f0cb8cf04366bebb7c264333a5f29f3d3416dd0d9f0' 
  AND token = 'QsPP7lHxZDiZNEqvSU2K891hNGpQ7GDRFKXsb5USp+g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00091

JSON explain

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