SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0cf3b9c6cf2432fd47c4a7d835fdc9c22236226c00e9e2b859669cfc489f1a48' 
  AND token = 'vW/oCikVkohjAY7KRo11GQ8Ox7YWFwMM1oBbE+JLscU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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