SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0f11e47355150ecf372958841ddf9a37d3587fbd0ab11712803d892a1168ba77' 
  AND token = 'qGkOGDgltDGe6iGaJ7Sz340QjBryq5DSZRlytFtYczI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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