SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1f98ba7d3f80459fe582b71e020f5805778d8b7621f8b1fa5ce23c1b927291b0' 
  AND token = 'eXKkTLhb5yBkn/uqQLFYd6VZrD+HGgQgLPRj5wMy+HA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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