SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b5c3b39ecd76c794694e09d943e8348f00b53364673498a9f635eb1e1f6a4b0e' 
  AND token = 'Ijs8G5s5mZN5IgeRH2Ph7UaMWT2YC6Ri3Qbxus/3dKo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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