SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c086583bd19bd125197886b0f746b3e63d16fdd7ed6cae20b1a4939e056c5f48' 
  AND token = '0nrRkUTDqDjHc5jBWnGWi0PkCdJn776AJf6wkfflbas=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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