SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f63e988b2da13e45e338bdffab326074eee681e6a22f39859d6485e06c87bcf6' 
  AND token = 'R3dYS3SJCLG8XVB92J9Rpoi6xLpd6I+j3Kn8S61KIns=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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