SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '755493585472d1da418cd346f3009aa0e36d4380ac7c517c90da534e6bdc5019' 
  AND token = 'vDFuEH3vZF5XKAC4V8hzBI4lXISLsDAuRNZ7lJmZpqA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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