SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c061863f4fdb0a9fa848d83168fa6f29c4f03e9edc5d90b893173353054c9081' 
  AND token = 'uqOSkLYEbKLHGmoEQZVyuHSgAtHWnp6Y1DJ3IhCOJCk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}