SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9003e9e91a6089d82c16c49318cac71bdd27f5bb20cdcc352e4dae3b5603e3ce' 
  AND token = 'MnnykbIAAtUy+siMqWcYCv+B4oU4qfC4PMfxiJJNS3A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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