SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd3c475c1fed9ffd3dc254880b5ddd2ba33dd7584d3823bbc8ca39c4f845db025' 
  AND token = 'XpadPX08/RdyN07tZSB0h7RNehtP3RcpratWX30Z3gI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}