SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0ba875140a766a1497fe735ee73b4c0125c9be29c168dbeff0426ae9fdf66ffb' 
  AND token = 'WeKdb3Xn9gUX5ROrFjTMbcYP+JgZSWRleMXBs84BVIg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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