SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c6c315802cf26a8e8f43d0008de9b181770fbeea3e9615e5b56127bb8132725a' 
  AND token = 'ghXEWoOfMy91Ml+1zJwZk3CyYqIxKlmUZOX9FRJUYoI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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