SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0e11b8b1b86479ce8f3edb9281fca5554455d8a8fcf72528e1bd2c8a7a1dd140' 
  AND token = 'vEOGrrbzpfSSzrjQznNgxuCC9VikD7ssQuhqAxruCDI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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