SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c48465db8c1204b195be2582dd6521c81c256e8b39e3ba7bfe9dbc21577af2e9' 
  AND token = '7Q7mm5o805aclGzCP1wuVONho9wFvarxefdFgDjCjbw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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