SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c20fb634c3a8eacbf51b80d99bca45b5fbd0bee8172e084284aafc0f08a96143' 
  AND token = 'sqeseCPmkBUYJDi6Fobw77RWhPGEh1aIQOgRcBNi/Xw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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