SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '254022b9b74580793cb4fbf6d2910804d8da5d3b685985cbeac39cbdb49f6cf2' 
  AND token = 'IpXAXrz1rFj1umodea2BOFOIB8aDkDr717A0/T3sRyY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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