SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ffc36301214a80970514cd093eb6988b987b96fb6a8ad0b1b538487723cdb24b' 
  AND token = 'hoWb8C5MR+5CrOBcXowvenrK3G720zWWNwVkgZrIMb4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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