SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e9adfaa79ea09220bb27027db726f163b60604a2192d5d30ecf072d2f96f76e4' 
  AND token = 'oXFi97AKquH+AWwLy6o2OgvAKRXm5r2gLoGip+uenvE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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