SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd1b3fb4029e9461c2761f84bb420062dfb450bd66094a05678f9c2035ef79aae' 
  AND token = 'jF092ZDyJQyyJ2KqeKLnx0bCPwvpTkKnG2CHdlP1jhk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00055

JSON explain

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