SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b44c23d886e0c79439d4a6bbe197714254abca58af124bb0ecddf2af84d94af3' 
  AND token = '9lqW5/p2jARs/VwWVRYPIFgWi7IJB0NXq1+iz3ZcDFQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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