SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5c2049fa5296f0f5a2e38a261a92fc6d8873988a2a98c07ce2920466fa373548' 
  AND token = 'l4dhO9XT1hxcPkBiJG+gYc5u3u39xHGzB1waXqZhhHY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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