SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'bf9f9dc935759ac8c5e5a9008cbbdbbce4358765a414da9ee221b03e52ee10d5' 
  AND token = 'EgeZxCuy/Iz8Sb+Oz5/f/ndS6r2xMn1HAySDouWMl5M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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