SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e819053b3beb210a97c4c724eecb21322b3dde398fe0eb86d64d4409014dd750' 
  AND token = 'cpneVNtlgFfqCfe9U6ZeEXWnKVT1i1phbwI0Fd8Comk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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