SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b7bf88233b9787441250f23e079072dc623a63b17ef8586bc7dc959508a586c5' 
  AND token = 'ufJUUSQm7SRXD9Ro+IXL1jJbk2LxA5DD0vVmju6F+Vw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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