SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5307ac32ce957075904630632c37019266d773d80fb43f30df1b1b703cfeabbb' 
  AND token = 'DSglv8NvxQqhTP212NL2mqkPZXtWyYwhxM90ry7PF8I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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