SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '85fd313e838758eae92095cad1a257da09cc15aaa88d98c1f4697273813b2063' 
  AND token = 'rnqFdHRLrGoKJnol2z8wD/GcU17ibDmP01hADM0T9XU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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