SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6590c3001eef92a546651a1960c4a8c1d1a89c61d5eeed7eb98ad185800203d1' 
  AND token = 'DLk70qNHah6siDUr13FlF+nk1x2vzCc9mXgtYCicrXY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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