SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'e2c0adecabc9da63293bd736479dbb9b053506c9320eecc312275bdb8e9704a4' 
  AND token = '/sePKDtZlE55ESxPgDFfp1H3XiFuwmBOxOJo31ldMzw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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