SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '47df2b4b1419d1a57504c39b3cd2bf7213c55688cb9ab139c23633b95d18c029' 
  AND token = '9SLkA3B5GnOOldiyMgfDufyo8sTAR+CP/bEx2unMG3w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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