SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c40a0fd53e16b2f919eb4f55cab98391b08ac5795294d36c6cf14433583424a1' 
  AND token = 'LHS34cLJkMR6sjJIZLULKXlgyT2TYOjFdy7zwA4shBI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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