SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5f1cc05c57735d8f5682ed75a3571ad9322836f8b0b4c98205bd252cb31e660b' 
  AND token = 'Ggg0FoI50z12DGaArm47+MBUxzbWcVmESb7nPGYbKP8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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