SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '97419e91191e30478a2723633764a8be8b238d7bfa612cab05000e78c6af5db8' 
  AND token = 'O2kJvOfYnvA852ERF3cYmDgsCzkAxeRDxrBafr4uCZU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00058

JSON explain

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