SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ae2d51110800a1b57c2289fbd2677ea646e6383d164065fb5d47e4920500b048' 
  AND token = 'GU27SwnNVwedzBph+t88veHziQGjhVgF3a3+s65Ifkk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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