SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2e1dfa96dfa99c3936a0f05eb53215e7abd7598394a8e19cdd96196b6df1f39b' 
  AND token = 'j14abduP5UMsCcB2bhvzWWLlEunLgRLaxxobGW1QuBY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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