SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7ce92a9aadcd0b1befcd90ada44c3f3eab3f88b206397f09f6f1a3d28eaa0e75' 
  AND token = 'UzG6b00xM3X3QFTOXIEAEAmy1ifM7YoV0ZTCeJhGXu8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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